Walking by the Abyss on Thin Ice - Chapter 27: Alien invasion

When Roland crossed Middle-earth with the Lord of the Rings system, Gandalf was organizing an expedition, the king under the mountain still did not return to his throne, the Hobbit’s adventure had not yet begun, and the world was still shrouded in shadows…

- Description from novelbuddy

Li Ke Lin (also Li Colin), a Chinese office worker, woke up to find himself suddenly no longer Li Ke Lin but instead Colin Lee, son of multi-billionaire in America. Having taken over the body of Colin Lee and carefully imitated his manners and bearings, his next goal is to inherit his father’s wealth. However, when his father lists the condition of marrying a woman who feels repulsed by Colin Lee’s (not Li Colin’s) dalliances, and whose very nature is the complete opposite of Colin Lee (not Li Colin), what must he do to gain her affection?!

The mid-level boss of my company’s AAA-game.

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates